Music in the 1943 movei "Jane Eyre"

Hello, music lovers. Hope to find the following information: In the 1943 movie "Jane Eyre", what is the piano piece that Jane plays on the first evening of Rochester's arrival, when he questions her proficiency as a piano player?
The movie soundtrack is well known, the composer who arranged the movie music is Bernard Herrmann. The particular piece I am asking about is, however, not Herrmann's own, but a classical piece: the orinal source escapes me, though. Appreciate any help.

lhotimla, November 12, 2012; 9:24 PM